This is starting to look interesting.
Protasiuk was entirely correct in refusing to depart without a destination TAF or METAR. Ironically, even if these had been available, the current Smolensk TAF was not forecasting fog, and the fog had not formed at the time of pre-departure planning. Of course he might have been concerned by reports of fog from other airfields in the region.
It is not just a question of visibility. MAK concludes that PLF101 at the time of the accident was 4.5 tonnes above the maximum landing weight for the existing conditions, i.e. the performance limited max landing weight. If met data had been available forecasting the tailwind on runway 26 this would have affected the flight planning assumptions, in particular the amount of reserve fuel carried. The alternative, RW08, presumably would not have been so limited because of headwind and the runway upslope, but appears to have no instrument approach procedure, so a visual approach only.
It could lend credence to the theory that the approach was not an attempt to land but to demonstrate to Blasik that conditions were such that a landing was impossible and to prove the point involved continuing the approach down to a point beyond what was prudent.